1. Field of the Disclosure
This disclosure relates generally to printers and, specifically, to devices for separating the rollers thereof prior to actual use, during shipping or during storage.
2. Description of the Related Art
Generally, in electrophotographic devices such as laser printers, a rubber coated developer roll is designed to be in contact with an aluminum photoconductor drum or PC drum. During operation of the electrophotographic device, it is expected that these two rotating members remain in constant contact with each other and that there is a nominal compression of the developer roll by the PC drum. However, prior to actual use or during shipping or storage, it is desirable to separate the rollers and PC drums. For example, some rollers and PC drums will chemically degrade other rollers and PC drums when maintained in stationary contact for long periods of time, especially at higher temperature and humidity conditions. This chemical degrading may result in defects in a printed page. In other cases, where one roll is softer than another roll and the softer roll may develop flat spots over time when maintained in stationary contact with the harder roll. The time period involved for such damage to occur varies with the chemistry and environment but may sometimes be on the order of six to eight weeks. Frequently, the shipping and shelf life of a product prior to use by the end customer exceeds this period. Moreover, the uncontrolled temperatures during shipment may accelerate the chemical reaction.
Some manufacturers solve this problem by installing a separator sheet between a roll and the PC drum. Others use a throwaway wedge that lifts the roll off the PC drum. Electrophotographic products are generally shipped with various rollers separated from each other using such approaches. During the unpacking and set up of the product, the customer is instructed to remove these separating devices and dispose of or recycle them. The product will not function correctly if these devices are not removed.
In addition to separator sheets or wedges, some manufacturers have used cam devices. These cam devices are designed to provide an interference fit between the cam and a roll shaft. However, such an interference fit can generate noise during normal printing operations and this further reduces the reliability of the cam. Further, any radial interference between the cam and the roll shaft can create a frictional drag such that the roll stalls or slips against the PC drum which can cause print defects.
Thus, there is a need to provide a mechanism that addresses at least some of the above problems and provide a reliable separation between the various rolls of an electrophotographic printer such as the developer roll and the PC drum without imposing unneeded frictional forces.